Researchers at the University of Southern California in LA has patented a project that would allow US Army officers to use coded smells to give orders.

These can be delivered silently, in the dark and when loud noise is drowning out speech. Furthermore, says the patent, the immediate reaction to a smell is emotional, rather than rational, so an odour trigger may encourage people to carry out orders without question.

A collar would hang round a soldier’s neck. The collar has a dozen cartridges, each containing a wick soaked in smelly liquid, a valve and a small propeller fan. Remote radio signals open selected valves and kick fans into life.

A soldier could be trained to associate specific actions with unmistakable odours. This would allow the smells to be used to jog memory – if you smell this, do that.

The system could also make training more realistic, with soldiers getting whiffs of desert dust, sea water or mud that are synchronised with audio and visual cues. The collar is close to the wearer’s nose, so the effect is immediate, and rapidly fades when the valve is closed.

Via New Scientist.